Pressure-relieving device.



W. 000mm. PRESSURE BELIEVING DEVICE. APPLICATION TILED DEG. 6.1907.

920,729. Patented May 4, 1909.

I VITNESSES:

@U HA/mm WILLIAM COOPER, OF IITTSBUBG, PENNSYLVANIA.

PRESSURE-BE LIE VING DEVICE Specification of Letters Patent.

Patented May 4, 1909.

Application filed December 6, 1907. Serial 'No. 05,386.

To all whom "it may concern:

Be it known that I, WELLIAM COOPER, a citizen of the United States, anda resident of Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement inPressure-Itelieving Devices, of waich the following is a specification.

My invention relates to fluid pressure relieving devices, and it has forits object to provide a device of this character that shall be simpleand durable in construction and reliable and effective in operation.

It is often desirable to provide means for automatically relieving thepressure in tanks or boilers when a predetermined internal pressure isexceeded. Various means for accomplishing this result have beensuggested in the prior art, including safety valves and other similardevices, but none of them are adapted for use with a boiler or pressurereceptacle, such as is employed in a system of refrigeration similar tothat illustrated and described in my co-pcnding application Serial No.@5385, filed of even date herewith. In systems of this kind, thepressure exceeds a safe value only under very extraordinarycircumstances and it is then de sirable to effectively and permanentlyrelieve the internal pressure, until necessary repairs can be effectedby a competent party. The problem is complicated by reason of the factthat the pressure-relieving t evice must be capable of continuouslyresisting the tendency of ammonia gas to force its way through andescape under normal pressures so that devices in which a thin film,diaphragm or bursting plate is utilized are obviously unsuitable.

The single figure of the accompanying drawing is a sectional elevationof a device constructed in accordance with my invention.

Referring to the drawing, the device here illustrated has the generalform of a cup or tray and comprises a metal disk 1 having an annularflange 2, the outer edge of which is finished into a plane surface; aconnecting pipe 3 and a cover plate 4. The cover plate 4 is a metal diskwhich is of su'flicient size to fit over the opening of the cup, makinga tight joint with the finished edge of the annular projection 2. Thepipe 3 is tapped through the wall of the cup and is intended I tocommunicate with the tank or boiler for which protection, againstexcessive pressures is desired.

The plate or disk l is sealed or secured to the edge of the projection 2by a brazing or soldering process, the brazing material being ofsufficient tensile strength to sustain working pressures within the cup.The pressure at which the two parts will be separated may be determined,not only by the composition and physical properties of the brazingmaterial, but also by the size of the cup and the thickness of theannular projection 2.

One advantage in the device of my present invention lies in the factthat the parts may easily be resoldered or sealed together again afteran excessive pressure has actuated the device, thereby the necessity ofreplacing the entire device or any one of its constituent parts isavoided. Another advantage results from the considerable thickness ofmaterial maintained at every point in the walls of the device, therebyobviating the leakage therethrough of such fluids as ammonia gas, whichreadily permeate thin metal parts. The brazing or soldering material isnever fused or melted, but is only ruptured by reason of a directpressure tending to pull the parts of the device asunder.

It is conceivable that the contour of the device may be varied and thatmany modifications in size and arrangement may be effected Within thescope of my invention, and I desire that only such limitations beimposed as are indicated in the appended claims.

I claim as my invention:

1. A pressure relieving device comprising a cup communicating with asource of pressure, and a plate or disk sealed over the opening in thecup by a material having a rela tively low tensile strength.

2. A pressure relieving device comprising a plate having an annularprojection the edge of the projection being finished into a singleplane, a source of pressure communicating with the cup thus formed, anda plate or disk fitted against the plane edge of the projection andnormally held in position by brazing.

3. A fluid-pressure relieving device comprising a plurality of partsbrazed or soldered together with a material of relatively low tensilestrength.

4. A fluid-pressure relieving device in which the resistance to openingis secured by a material of lower tensile strength than the integralparts of the device.

5. A fluid-pressure relieving device comprising two parts fittedtogether and held in position by brazing or soldering with a material ofrelatively low tensile strength.

6. A fluid-pressure relieving device comprising a plurality of partssealed together with a material of relatively low tensile strength.

7. A pressure-relieving device comprising a cup or chamber, a plate ofmaterial thickness fitted over the opening therein, and means comprisinga suitable brazing material for holding the plate in position until thepressure in the chamber exceeds a predetermined amount.

8. A pressure-relieving device comprising a shallow cup or chamberhaving its edges finished into a single plane, a plate of materialthickness fitted over the opening in the cup or chamber, and an annularstrip of solder for holding the plate in position by adhering to theplate and to the Walls of the cup or chamber.

In testimony whereof, I have hereunto subscribed my name this 4th day ofDec, 1907.

WILLIAM COOPER. Witnesses:

R. J. DEAnBonN, BIRNEY HINEs.

